Rapid profiling of fish cell nitrogen metabolism with single-cell Raman spectroscopy: Unveiling enzyme's role in ammonia detoxification.

Ammonia is a prevalent aquatic pollutant that disrupts cellular functions and energy metabolism in fish, posing significant environmental and health threats. This research investigates the critical role of arginase 2 (ARG2) in mitigating ammonia toxicity in fish cells and its implications in adapting to nitrogen metabolism under high ammonia exposure. Through a CRISPR-Cas9 engineered ARG2 knockdown (KD) in the Epithelioma Papulosum Cyprini (EPC) cell line, we first investigated the biochemical responses of ARG2 KD and wild-type (WT) EPC cells to ammonia stress (NH4Cl treatment), showing diminished urea production and decreased cell viability in ARG2 KD cells. Subsequently, single-cell Raman spectroscopy analysis revealed that ARG2 KD cells exhibited profound metabolic shifts, including changes in protein, nucleic acids, lipid and sugar levels, showing the adjusting role of ARG2 in the balance of carbohydrate and nitrogen metabolism. Furthermore, the upregulated responses of various amino acids, such as glutamine, arginine, alanine, glutamic acid, glycine, histidine, phenylalanine and valine, in WT cells after NH4Cl treatment diminished in ARG2 KD cells except for the decrease in aspartic acid, indicating a switching effect of ARG2 in nitrogen metabolism under ammonia stress. This study highlights ARG2's essential role in ammonia detoxification and emphasizes ARG2's protective function and its importance in metabolism, shedding light on the adaptive mechanisms fish cells deploy against high ammonia environments. These insights contribute to deep understanding of aquatic organisms' molecular responses to environmental ammonia pollution, offering potential strategies for their protection.

Iodine-catalyzed regioselective direct sulfenylation of uracil with sulfonyl hydrazide as sulfur source under solvent free conditions.

A facile method was developed for the selective thioetherification of uracils using sulfonyl hydrazide as the thioetherification reagent. This method offers advantages such as avoiding the use of additives and expensive metal catalysts, and providing good to excellent yields of various uracil thioethers. Experimental studies have demonstrated that the reaction follows a free radical pathway. Notably, the reaction can be carried out without solvent.

Pregnancy outcomes in Chinese women with mechanical heart valves receiving warfarin treatment throughout pregnancy: 14-year experience.

OBJECTIVE: The purpose was to evaluate pregnancy outcomes and risk factors associated with fetal complications in Chinese pregnant women with mechanical heart valves (MHVs) taking low-dose warfarin, aiming to fill in the research gap of this area. METHODS: Between June 2010 and Aug 2023, 122 patients with MHVs who had 151 pregnancies and received warfarin throughout pregnancy were included. We compared them with 302 paired pregnancies without warfarin treatment. Binary logistic regression analyses were performed to explore risk predictors of fetal complications. RESULTS: Pregnancy loss rate was 37.1 % in women taking warfarin, compared to only 4.6 % for those without warfarin exposure in pregnancy (RR = 8.00, 95 % CI: 4.61-13.90). In pregnant women with MHVs, there were 34 spontaneous abortions, 22 stillbirths and 1 neonatal malformation. In the first, second and third pregnant trimesters of women with MHVs, fetal complication incidences were 19.2 %, 9.9 % and 8.0 %, respectively. 86.0 % of fetal complications occurred in women taking a warfarin dose ≤5 mg/d, accounting for 94.0 % of the total population. The newborns' birth weight, gestational age and 1-minute Apgar score were significantly lower in pregnancies treated with warfarin compared to those without warfarin exposure. Only 2.0 % of postpartum hemorrhage and no thrombosis or maternal mortality data were collected in pregnant women on warfarin in this study. CONCLUSION: Most Chinese pregnant women take a warfarin daily dose ≤5 mg and they might have only around 60 % chance of giving birth to a live baby without maternal complications.